What does the handbook say ,a recent article in the DT said the service indicators on DB were almost faultless and the engineers would trust their lifes to them,my experience of them agrees. Its not just a glorified clock it looks at a multitude of points and uses a complex equation to work out the recommended service intervals.

The car is '04'and coming around 30k miles in total.

If those numbers are correct, that means you have 6 year old car which has done 30,000 miles. That's fairly low mileage for its age, so I guess service indicators would take into account that it's not very often getting up to optimum working conditions